ALLOWANCE FOR LOAN LOSSES

As discussed in Note 1, the Company estimates for currently existing and probable losses for its mortgage loans that are considered impaired. A loan can be considered impaired even if it is not delinquent. The following table summarizes the aggregate activity for the portion of the allowance for loan losses that relates to the securitized mortgage loan portfolio for the periods indicated:



	Three Months Ended
	March 31,
	2012					2011
	Commercial			Single-family		Commercial			Single-family
Allowance at beginning of period	2,268			231		4,200			270
Provision for loan losses	60			—		250			—
Credit losses, net of recoveries	(987		)	—		(213		)	(21		)
Allowance at end of period	$	1,341		$	231	$	4,237		$	249

The following table presents certain information on impaired securitized commercial and single-family mortgage loans as of March 31, 2012 and December 31, 2011:



	March 31, 2012						December 31, 2011
	Commercial			Single-family			Commercial			Single-family
Unpaid principal balance of impaired securitized loans	$	1,814		$	3,029		$	4,724		$	3,000
Basis adjustments related to impaired securitized loans	—			59			8			48
Amortized cost basis of impaired securitized loans	1,814			3,088			4,732			3,048
Allowance for loan losses	(1,341		)	(231		)	(2,268		)	(231		)
Investment in excess of allowance	$	473		$	2,857		$	2,464		$	2,817

The Company recognized $25 and $40 of interest income on impaired securitized commercial mortgage loans and single-family mortgage loans, respectively, for the three months ended March 31, 2012 compared to $86 and $42, respectively, of interest income for the three months ended March 31, 2011.